Bracket attaching fixture for fastener driving tool



E. F. PFAFF 3,019,441

BRACKET ATTACHING FIXTURE FOR FSTENER DRIVING TOOL Feb. 6, 1962 4 Sheets-Sheet 1 Filed Jan. 4, 1956 Feb. 6, 1962 E. F. PFAFF 3,019,441

BRACKET ATTACHING FIXTURE FOR FASTENER DRIVING TOOL Filed Jan. 4, 1956 4 Sheets-Sheet 2 FICSl INVE/vraf E. F. PFAFF Feb. 6, 1962 BRACKET ATTACHING FIXTURE FOR FASTENER DRIVING TOOL 4 Sheets-Sheet 5 Filed Jan. 4, 1956 FIGJS.

Feb. 6, 1962 v E. F. PFAFF 3,019,441

BRACKET ATTACRING FIXTURE FOR FASIENER DRIVING IooL Filed Jan. 4, 1956 4 Sheets-Sheet 4 ATTORNEY United States Patent Oiice 3,(ll9,441 Patented Feb. 6, 1962 3,019,441 BRACKET ATTACHING FIXTURE FOR FASTENER DRIVING TOOL Elmer F. Pfaff, Mantua rllownship, Ohio, assigner, by

mesne assignments, to Olin Mathieson Chemical Corporation, a corporation of Virginia Filed Jan. 4, i956, Ser. No. 557,321 9 Claims. (Cl. 1-44.5)

This invention relates to a 'fixture for attaching a bracket to a structural member and more specifically to such a fixture for use with a fluid powered fastener driving tool.

The xture of this invention is intended primarily for use in attaching brackets to cylindrical members such as posts, columns, railings or other similar structural members which may be either vertically or horizontally disposed. The fixture may be used in conjunction with fastener driving tools such as those powered by an explosive charge as well as certain types of riveting, cutting or welding tools. To facilitate a clear understanding the fixture will be described in the environment of an explosively powered fastener driving tool of the type disclosed in copending U.S. patent application Serial No. 355,034, filed May 14, 1953, now U.S. Patent No. 2,945,- 236 granted July 19, 1960 but it is to be understood that the invention is not to be limited to this environment.

Brackets may be secured to structural members in various conventional manners such as by welding a metal bracket to a metal post, by drilling a hole through the bracket and into a post and then bolting or screwing the members together or by clamping the bracket to a post. It is, however, much simpler and more economical to attach small brackets such as a street sign holding bracket to a post by a fastener driven through the bracket and into the post by a fastener driving tool such as the conventional explosively powered tool described in the aforementioned patent, Irrespective of the mode of attachment it is necessary that the bracket be properly positioned on the structural member prior to effecting the permanent attachment. The bracket may, of course, be temporarily held in place on a post by a C-clamp or other similar clamping means or it may be held in place by hand. The latter mode of temporary attachment has obvious disadvantages when using power tools and should not be encouraged. Since the tool which is to effect the permanent attachment must be properly positioned in respect to the bracket and structural member irrespective of the mode of temporary positioning of the bracket, much time, effort and manpower may be saved if the bracket is first properly positioned on the attaching tool and the tool is then properly positioned on the post or similar structural member.

Fluid powered fastener driving tools generally incorporate certain safety features for the protection of nearby personnel and material. These features are fully described in the aforementioned patent. Generally such safety features include means to prevent a fastener from being fired from the barrel and discharged into the air in the manner of a projectile by permitting the tool to be fired only when it is properly positioned against the surface into which the fastener is to be driven. A shield or some other means are invariably provided to prevent a fastener from causing injury in the event that it should ricochet rather than imbedding in the intended surface. It is, of course, highly desirable to retain these safety features when the tool is used in conjunction with a special xture. In driving a fastener into a post the fastener might be driven clear through the structural member, irrespective of the particular type of fastener driving tool employed. It is, therefore, highly desirable that means be provided to prevent a fastener which is driven through a post or similar structural member from ying through the air in the manner of a projectile and causing injury.

It is, therefore, an object of this invention to provide a fixture for properly positioning a bracket relative to a structural member prior to fastening the bracket to the structural member.

Another object of this invention is to provide a fixture to which a bracket may be secured so that it is merely necessary to properly position the fixture on a structural member rather than temporarily securing the bracket to the structural member prior to permanently attaching the bracket and structural member.

Another object of this invention is to provide a fixture for use with a fastener driving tool wherein means are provided to prevent the fastener from being discharged if the bracket and fixture are not properly positioned relative to the structural member to which the bracket is to be attached.

Another object of this invention is to provide a fixture which will prevent a fastener which is driven through a post or similar structural member from entering free flight in the manner of a projectile.

Other objects and advantages will become apparent from the following description and drawings in which:

FIGURE l is a perspective view of the fixture clamped around a post and attached to an explosively powered fastener driving tool;

FIGURE 2 is a perspective view of the fixture attached to the tool with the bracket held in the fixture and the fixture in the open position ready to be clamped around a post or similar structural member;

FIGURE 3 is a top view of the fixture attached to the tool with the fixture in an intermediate position while receiving a structural member;

FIGURE 4 is a longitudinal sectional schematic view of the front portion of a conventional explosively powered fastener driving tool suitable for use in conjunction with the subject fixture, the tool being shown in the inoperative or safe position;

FIGURE 5 is a view similar to FIGURE 4 but with the tool in the operative or ready to fire position.;

FIGURES 6, 7 and 8 are side views of the lixture looking in the direction of arrow A in FIGURE 1 and illustrating the function of a locking device; FIGURE 6 shows the fixture in an intermediate position while being closed; FIGURE 7 shows the fixture in the closed position but prior to being locked; and FIGURE 8 shows the fixture in the locked position;

IGURES 9 through l1 are sectional views of the tixture taken generally on the line B-B in FIGURE 1 and showing one embodiment of a bracket holding means and a fixture closing or clamping means; FIGURE 9 shows the fixture in the fully open position as in FIG- URE 2; FIGURE 10 shows the fixture engaging the post and in an intermediate position similar to FIGURE 3; and FIGURE 11 shows the fixture in the closed position similar to FIGURE l but in the tiring position with the tool barrel muzzle pressed against the bracket;

FIGURE l2 is a sectional View taken on the line 12-12 in FIGURE 9 with the bracket removed from the bracket holder;

IFIGURE 13 is a sectional view taken on the line 1 3-13 in FIGURE l2;

FIGURE 14 is a sectional View showing another embodiment of a bracket holder;

FIGURE l5 is a sectional view taken on line 15-15 in FIGURE 14.

FIGURE 16 is a sectional View taken generally along the line B-B in FIGURE l and showing the tool positioned against a work piece but prevented from assuming the operative or ready-to-fire position because a bracket has not been properly secured in the fixture.

A typical tool with which this fixture may be used is fully described in the aforementioned patent. Following is a description of the structural and functional features of such a tool to the extent necessary for a clear understanding of the relationship between the tool and the fixture.

Referring to FIGURES 4 and 5, the tool 1 includes a barrel 2 telescopically received in a housing 3 and urged outwardly or to the right with respect to the housing by a spring 4. The housing includes a hand grip portion 5 which may be of resilient material. The inner or left end of the spring is seated against an abutment 6 in the housing projecting from either the housing as shown or from the barrel as disclosed in the aforementioned application and the right end of the spring is seated against an inwardly directed abutment 7 on a tubular member 8 which is also telescopically received in the housing 3 and telescopically receives the barrel 2. A shield 9 is secured to the tubular member 8 in any conventional manner as by welding 10. The barrel muzzle end 1l projects through aligned openings in the tubular member 8 and shield 9. A barrel protector cap 12 is threaded to the barrel muzzle end 11 and secures the shield and tubular member 8 on the barrel 2. When pressed against a work piece W, as shown in FIGURE 5, the shield 9 protects nearby personnel and material from the effects of the muzzle blast resulting upon firing of the tool as well as preventing escape of ricocheting fasteners. The housing 3 and the shield tubular member 8 are interlocked to prevent relative rotation of these members. In this particular tool the interlock is effected by providing the housing and tubular member with cooperating mating hexagonal configurations as shown in FIGURE 1. However, any noncircular cross sectional configuration would be satisfactory, or alternatively, the housing and tubular member may be keyed together through a conventional key and groove arrangement. However, the hexagonal configuration has an advantage in permitting the shield 9 to be rotated into various angular relationships with the housing 3 by removing the cap 12, withdrawing the tubular member 8 lfrom the housing and rotating the tubular member prior to insertion into the housing. The tool may therefore be held in the normal position irrespective of the position of the workpiece, as will be evident hereinafter.

A cartridge 13 is received in a ybreech plug 14 which is in turn received in a chamber 15 in the barrel breech end 16. A fastener 17 is received in the bore 18 of the barrel 2. it should be noted that fastener 17 may be a separate element as shown or if desired, it may be attached to the cartridge 13 to form a unit assembly. Movement of the barrel 2 inwardly or to the left and into abutment with a breech block 19 automatically cocks a cartridge tiring mechanism which includes a firing pin .2G and firing trigger 21. Upon depressing the trigger 21, shown in FIGURE 1, the firing mechanism drives the firing pin 20 forward or to the right with sufficient force to detonate cartridge 13.

It should be noted that the tubular member S is free to telescope in the housing 3 independently of the barrel 2 but that when the barrel 2 is telescoped into the housing 3 the engagement between the shield 9 and barrel cap 13 cause the shield and tubular member 8 to telescope inwardly along with the barrel 2.

The conventional tool is provided with means to prevent firing of the cartridge 13 unless the barrel breech end 16 engages the breech block 19 as well as means to prevent firing the cartridge if the longitudinal axis of the barrel is at an unsafe angle with respect to the surface into which the fastener 17 is to be driven. These features are retained when the tool is used in conjunction with the subject fixture but they do not directly affect the operation with the fixture.

The fixture 30 of the present invention replaces the shield 9 of the conventional tool described immediately above.

Referring to FIGURES 1 through 3 the fixture 30 includes a box 31 having welded or otherwise secured to one side a hexagonal tubular extension 32. Box 31 replaces shield 9. The hexagonal tubular extension 32 replaces and is the full mechanical equivalent of the shield tubular member 8. The box is formed of two sections, 33 and 34, interconnected by a hinge 35, which fixed box half 33 is secured to the tubular extension 32. Opposite walls of each box half 33 and 34 are provided at the parting line with cut-out portions 36 and 37, respectively, which receive a structural member S. The longitudinal axis of the cut-out portions is perpendicular to the longitudinal axis of the tool barrel bore 18 and parallel to the axis of the hinge 35.

The box halves are locked together in the closed position as shown in FIGURE 1 by a U-shaped locking arm 39 having a notch 40 which engages a locking pin 41 on the hinged box half 34.

The U-shaped locking arm 39 is pivoted to the fixed box half 33 by two pivot pin bolts 42 and 43. One of the arms 414 of the U-shaped locking arm is longer than the other and the free end of the longer arm is provided with the notch 4G. As shown in FIGURES 6 through 8 the locking arm 44 is provided with a cam portion 45 so arranged that should the notch 40 be in its downward position when the hinged box half 34 is closed against the xed box half 33, the locking pin 41 will engage the cam surface 45 and move the locking arm upwardly to align the notch 40 with the locking pin 41. A tab 46 to engage the fixed box half 33 is provided on the bight portion 47 of the locking arm to prevent the notched end of the arm from being depressed so far that the locking pin 41 will not engage the cam surface 45. When the box 31 is closed it is then merely necessary for the tool operator to pivot the bight portion 47 of the locking arm 39 outwardly and the opposite end of arm 44 inwardly to engage the notch 40 and locking pin 41. The arm 39 is pivoted in such a manner that when the two box halves 33 and 34 are locked together the tool housing 3 fully receives the tubular portion 32 of the fixture 30 and the barrel 2 with the front end of the housing almost abutting against the box. Should the operator inadvertently fail to move the locking arm 39 into locking engagement with the pin 41, -upon movement of the tool into the tiring position with the housing 3 telescoped to the right over the barrel 2 the top front end of the housing 3 will engage the bight portion 47 of the arm 39. Because of the angular inclination of the bight portion of the arm with respect to the top front end of the housing and the pivotal relationship of arm 39 about pivot Kbolts 42 and 43, the inclined bight portion will be moved outwardly while the opposite end of locking arm 44 is moved inwardly by the housing and the notch 46 and locking pin 41 will be automatically interlocked. Y

A bracket B to be attached to a structural member S is held in place in the fixed box half 33 by a bracket holder 48 secured in the xed box half. The bracket holder 48 may have any required configuration to properly position the bracket B adjacent the structural member S prior to driving the fastener 17. The holder may be secured to the box in any appropriate manner, as by bolts 49 toV facilitate changing the holder when it is desired to use a different type of bracket.

As shown in FIGURES 9-13 the bracket holder 48 is a block of metal having a tapered face 5G and upstanding flanges 51 and 61 on opposite ends of the tapered surface. Secured to an adjacent wall of the fixed box half 33 is a spring pressed detent assembly 52. The axis of lineal movement of the detent intersects and is substantially perpendicular to the tapered face 50 of the bracket holder. The detent assembly comprises a tube 53 secured as by welding to the wall of the box. A bore extends through the tube and the adjoining supporting wall of the box 33 and receives the detent 5.4, a spring S5 and a closure plug 3 56 threaded into the tube. The plug may be inserted or removed from outside the box by first removing the U- shaped arm. The spring biased detent 54 may advantageously engage an orifice in the adjacent leg of ybracket B, the better to hold it between the flanges 51 and 61 of the holder 48.

Alternatively, as shown in FIGURES 14 and l5, one of the flanges 51 is provided with a cut-out portion 57 which receives a leaf spring 5S. The spring is secured to the bottom of the holder 4S by a bolt 59 and has a free arm 70 projecting upwardly through the cut-out 57 at substantially right angles to the attaching portion. The free end or tip 71 of the arm passes through the cut-out 57 in the flange 51 and projects inwardly from the flange. The bracket B is received on the tapered face 50 of the bracket holder 48 between the free end 71 of the spring arm 7? and the opposite liange 61 of the bracket holder. The bracket B used with the above described embodiment is an angle bracket provided with holes in one leg to which a sign or other article may be attached and a second imperforate leg through which the fastener element is driven.

Referring to FIGURES 9-12 and 16 the muzzle end 11 of the tool barrel 2 has threaded thereto a special barrel extension 60. The other end of the extension 6l) is threaded into the conventional barrel protector cap 12. The cap 12 secures the fixture 30 tot the tool 1 in the same manner as the shield 9 is secured to the tool. The barrel extension 60 increases the effective length of the barrel 2 sufficiently to permit the breech end 16 of the barrel to seat against the breech block 19 of the tool when the barrel cap 12 is pressed against the lbracket B and structural member S as shown in FIGURE 16, the length of the barrel extension 69 is such that when the bracket B has not been emplaced in the bracket holder 43, the barrel breech 16 will not seat against the breech block 19 and the tool therefore cannot be fired. The extension 6% is required because the distance between the front end of the barrel cap 12 and the ibase of the cut-out 36 is greater than the equivalent depth of the conventional shield 9. The extension 60 should be of such length that the barrel breech 16 cannot engage the breech block 19 should a bracket B not have been emplaced in the bracket holder 48 thus preventing rinig of the tool under these circumstances. The extension 60 should be as long as possible, or at least long enough to permit the barrel breech 16 to seat properly against the breech block 19 when a relatively thin bracket is emplaced in the holder 48, but it must not be so long as to permit the barrel breech to engage the breech block when a bracket is not in the holder.

The hinged box half 34 is provided with the closing bar 62 which is lixed to the wall adjacent the hinge 3S. When the box is open, as shown in FIGURES 2 and 9, the closing bar 62 projects in a direction generally in front of the barrel cap 12. As the xture 3) is brought in contact with the structural member S the closing bar 62 engages the structural member and closes the pivoted box half 34 against the xed box half 33. A hinge stop 65 is attached to the xed box half 33 to prevent the pivoted box half 34 from opening so -widely that the closing bar 62 would be ineffective to engage the structural member S and close the box. Bar 62 is notched as a slight continuation of the semicircular cut-outs 37, as shown in FIG- URES 3, 9-11 and 16, only sufficiently to provide a hook action the better tot engage with structural member S, without interfering with reception of member S in the cut-outs 37.

The lateral surfaces of the box halvcs 3'3 `and 34 are provided with longitudinally extending indicator lines 63 parallel to the longitudinal axis of the tool barrel 2. The fixed box 33 carrying the bracket holder 48 is additionally provided with an index mark 64 which indicates the plane of the bracket holding face 50 and of one of the legs of the bracket B.

The box is fabricated from steel or other suitable material to resist penetration by a ricocheting fastener 17 or a fastener which may be driven completely through the structural member S. As an added precaution against a fastener being driven completely through the structural member and the box, the box wall directly opposite the muzzle of the barrel may be provided with an added thickness of metal if necessary to positively assure that the stud cannot pass through the wall and enter free iiight.

The operation of the fixture and the tool is as follows: The bracket B is inserted into the bracket hol-der 48 and held in place by either the spring detent assembly 52 or the leaf spring 58. With the box 31 in the open position as shown in FIGURES 2 or 9 the tool and box are moved toward the structural member S. The structural member engages the closing bar 62 which pivots the hinged box half 34 against the fixed box half 33. In this position the structural member S is nested in the cnt-out portions 36 and 37. As the hinged box half 34 closes against the fixed box half 33, the locking pin 41 engages the cam portion 45 of the locking arm 44 should the notched end of the arm 44 be in its downward position and forces it to its uppermost position. The tool operator should then move the bight portion 47 of the arm 39 upwardly or away from the tubular extension 32 to interlock the notch 40 and the locking pin 41. The operator now properly positions the fixture and bracket adjacent the structural member by observing index marks 63 and 64 on the box. The tool 1 is then pressed toward the box 31 telescoping the tool housing 3 with respect to the barrel 2 and tubular extension 32. Should the operator inadvertently fail to lock the box halves together as previously described, movement of the tool toward the box will cause the top front end of the housing 3 to engage the inclined bight portion 47 of the locking arm 39 automatically locking the box in the closed position. Continued movement of the tool 1 toward the box 31 causes the bracket B to be clamped between the structural member S and the cap 12, the barrel breech end 16 to abut against the breech block 16 and cocks the firing mechanism. The trigger 21 is then depressed causing the tiring mechanism to detonate the cartridge 13 driving the fastener 17 through the bracket B and into the structural member S securing the bracket and structural member together. The tool 1 is then released allowing the tubular extension 32 and barrel 2 to telescope outwardly with respect to the housing 3 to the position shown in FIGURE l. By depressing the locking arm bight portion 47 into contact with the tubular extension 32 the notch 40 and locking pin 41 are disengaged and it is merely necessary to withdraw the tool and fixture from the structural member S at which time the bracket B will be withdrawn from the bracket holder 48.

As previously described the fixture 30 provides several interrelated safety features. First, the closing arm 62 automatically closes the two box halves 33 and 34 as the fixture 30 is brought into engagement with the structural member S. Second, a stop on the fixed box half 33 prevents the hinged box half 34 from opening so wide that the closing bar 62 is inoperative to engage the structural member S as described immediately above. Third, the locking pin 41 on engaging the cam portion 45 on the locking arm 39 automatically pivots the notch 4t) into proper alignment with the pin 41 when the box halves 33 and 34 are closed. Fourth, when the tool 1 is depressed into the firing position the tool housing 3 engages the inclined bight portion 47 of the locking arm 39, pivoting the notch 40 into locking engagement with the locking pin 41. Fifth, the tool barrel extension 60 is of such length that the barrel cannot be moved to its firing position unless a bracket B is inserted in the bracket holder 48.

It is to be understood that although this invention has been described with reference to an explosiv-ely powered fastener driving tool it is not to be limited to this environment but is equally suitable for use with other types of fastener driving tools and certain types of other tools, such as welding, riveting or cutting tools. It is also to be understood that this invention is not to be limited to use with any particular type of structural member or bracket but may be adopted for use with various combinations of brackets and structural members. Although several specific embodiments, components and details are set forth in the foregoing description, it will be understood that various changes may be made therein without departing from the spirit and scope of this invention and that this invention is therefore not to be limited to such specific embodiments, components or details except as set forth in the appendent claims.

I claim:

1. In an explosive powered tool having a barrel for driving a fastener element into a structural member, a fixture comprising a box having cut-out portions in opposite walls to receive said structural member, said box being divided into hinged sections, one section pivoting on the other, each box section including a portion of each of said cut-out portions, an arm fixed to said one section for engagement with said member to close said sections about said member by interfering with said member unless the sections are so closed, a second arm pivoted to the other of said box sections, said arm having means to interlock with said one box section, and cam means on said arm to properly position said arm for interlocking with said one box section as said box sections are closed against each other.

2. A tool for attaching a bracket to a relatively long transversely circumscrable structural member, said tool comprising a housing telescopically receiving a barrel, said barrel having means for driving a fastener through said bracket and into said structural member whereby said bracket is attached `to said structural member; a fixture having a portion telescopically received by said housing, said fixture having substantially completely circumscribing means to operatively engage said structural member for positioning said barrel with respect to said structural member and means lto properly position said bracket adjacent said structural member for attachment thereto by said fastener.

3. The tool of claim 2 wherein said fixture comprises a pair of separable sections at least one of which has a cut out portion to operatively receive said structural member therebetween, and means to lock said sections together, said locking means comprising on one of said sections a pivoted lever including a latch portion cooperating with the other section, said lever including a portion having means cooperating with said tool housing to rock said lever and lock said sections together when said housing is telescoped toward said fixture.

4. in a tool, a fixture for positioning said tool on a structural member, said fixture being telescopically received by a housing portion of said tool, said fixture coniprising a pair of hinged sections 4and means to lock said sections together when said fixture and said housing are telescoped inwardly with respect to each other.

5. The tool of claim 4 wherein said locking means comprises a first arm pivoted to lone of said sections and a second arm pivotable into and out of the path of said housing as the hinged sections are closed, said second `arm including cam means to be engaged by said housing when said housing is telescoped with respect to `said fixture to cause said first arm to interlock with the other section.

6. The tool of claim 5 wherein said first arm is provided with a notch which engages a pin on said other section to lock said sections together.

7. The tool of claim 5 wherein said first arm is provided with cam means to engage said pin as said sections are closed to pivot said arms so that said notch is aligned with said pin for subsequent locking engagement of said pin by said notch.

8. A tool for attaching a bracket to a workpiece, said tool including -a moveable housing telescopically receiving a portion of a bracket positioning fixture, said fix* ture being normally urged outwardly with respect to said housing, said fixture comprising a workpiece receiving member, said workpiece receiving member comprising a pair of separable sections the first of which is supported on the tool and both of which are hinged together and at least one of which has a cut out portion to receive and clamp said workpiece therebetween, means on the other of said sections to close said sections against each other as said first section is urged against said workpiece, the last said means comprising `an arm fixed to the other of said sections; and means to lock said vsections in the closed position, said locking means comprising a latch member pivoted to the first of said sections and having means movable into locking engagement with said other section, said latch further having means cooperating with said housing on movement thereof to tool operating position to move said latch into locking engagement with said other section.

9. A fixture for the muzzle end of the barrel of an explosive powered tool comprising a structural member engaging means, said means being defined by a hollow box having opposite wall means and opposing cut-out portions in said wall means to receive a structural member in Vat least substantially complete circumferentially surrounded relationship, said means being divided into separable sections defined by la plane passing through said cut-out portions in said wall means to permit said sections to be separated to facilitate reception of said structural member first in the part of the cut-out portions in one of -said sections, means on said section for mounting said barrel in operatively aligned relationship, pivot means mounted on said wall means interconnecting said sections ,for articulation with respect to each other about said plane, means on the other of said sections to lautomatically close said sections `against each other as said structural member is being received in said cut-out portions of said first section, and latch means mounted on said first section in movable relationship to positively interlock said 'sections with respect to each other when said tool is operatively thrust against said structural member so as to operatively engage said automatic closing means and first and second sections with said structural member, said latch means preventing operation of said tool when not moved to the interlocking position.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT oEEICE CERTIFICATE OF CORRECTIUN Patent Noe SVOlQqQAl February 6Z 1962 Elmer l?o Pfaff It is hereby certified that error appears infbheabove nmnberel patent requiring correction and that the -sad Letters yPzaferfc. should read as corrected below.

Column 8x, line l forb the claim reference numeral Q5H read m Signed and sealed this 29th day of May 1962D (SEAL) Attest:

DAVID: L. LADD Commissioner Aof Patents ERNEST W. SWIDER Attesting Officer 

